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Optical & Industrial Glass Suppliers

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Glass Filter

Product Information
Colored and filter glass selectively absorb light in the visible wavelength range.
With a comprehensive UK stock, we can provide virtually any size, shape and quality required.
With the range extending to over 60 types, we now include the following filter types in the visible wavelength range from 200 nm upwards:

  • Band pass filters, which allow required ranges to pass through selectively
  • Long pass filters, which block unwanted shorter wave ranges
  • Short pass filters, which block unwanted longer wave ranges
  • Neutral density filters, which have a virtually constant transparency especially in the visible range
  • Conversion filters, which due to their spectral range increase or reduce the color temperature of radiation sources

Our filters are divided into the following groups:

  • UG Black and blue glass which permits the transmission of UV light
  • BG Blue, blue-green and band glass
  • VG Green glass
  • GG Yellow glass which permits IR light transmission  
  • OG Orange glass which permits IR light transmission
  • RG Red and black glass which permits IR light transmission
  • NG Neutral glass with virtually constant radiation weakening in the visible range
  • N-WG Colorless glass with different cut-off positions in the UV range and which allows IR and visible light transmission
  • KG Virtually colorless glass with high transmission of visible light and absorption of radiation in the IR range
  • FG Blue and brown colored glass (conversion glass)

Optical glass filters are used in a host of different applications including industrial measurement, control and regulation technology, analytical measurement, research and development all the way through to environment protection and medicine with which the filters either permit or block the transmission of specific spectral ranges. We have listed a number of possible applications below:

"Keep it out of your eyes "
KG3 and KG5, which stand out because of their high transmission of visible light and effective absorption in the infra-red range (especially 1064 nm for Nd:YAG-Laser) are used as components in protective glasses and windows for lasers.

"Cool light in the operating theatre" – KG1 and KG3 in operating lights
The extensive colour neutrality of our heat absorption filters KG1 – KG5 in the visible spectrum prevents colours being falsified in the operating area.

"Seeing in the dark"

Spotlights which are equipped with RG filters only allow IR radiation to be transmitted and when in operation appear black to the observer. Together with cameras sensitive to infra-red radiation, they can be used for monitoring tasks without being noticed.

Basic glass
Ionically colored glass
Colloidally colored glass
Forms of Supply
Polished filters:
Either as polished plates or round discs with processed edges. Upon request, they are available thermally strengthened and / or with a protective / antireflection coating.

Filter glass blanks with processed edges, either as rectangular plates or round discs with matt surface and processed edges.

Standard forms with non-processed edges:
Plate sizes 165 mm x 165 mm + 3-0 mm
Plate thickness 3.5 mm ± 0.5 mm and 4.5 mm ± 0.5 mm

Minimum thickness from 1 mm - 480 mm
0.1 mm
Tolerances Up to 0.001 mm
Surface quality Up to P 4 in compl. with DIN ISO 10110

Quality Assurance

Filter glass production is subjected to continuous quality control with continuous documentation of the respective production steps. As far as is permitted by the transparency of the glass, the interior quality of our glass is checked for bubbles, smears etc. Powerful measuring devices are then used to perform a final check on the filters.

For more information please contact the technical team at Skan